SYNTHESIS AND REACTIVITY OF SILICON TRANSITION METAL COMPLEXES - 44 -METALLOSILANOLS AND METALLOSILOXANES - 17 - REGIOSPECIFIC HYDROXYLATION OF METALLODISILANES OF THE IRON-GROUP - AN IMPRESSIVE EXAMPLE OF THE TRANSITION-METAL EFFECT

Reaction of the ferriodisilanes C5R5(OC)(2)Fe-Si2H5 [R = H (la), Me (I b)] with dimethyldioxirane leads to selective insertion of oxygen into the alpha-Si-H bonds to yield the ferriodihydroxydisilanes C5R5(OC)(2 )Fe-Si(OH)(2)-SiH3 [R = H (2a), Me (2b)]. Another access to yield 2a i s opened by hydrolysis of the dichloro(ferrio)disilane Cp(OC)(2)Fe-SiC l2-SiH3 (3a). Treatment of the pentachloro (metallo) disilanes C5H5(OC )(2)Fe-Si2Cl5 (4a) and C5Me5(OC)(2)Ru-Si2Cl5 (4b) with water results i n regiospecific hydroxylation of the beta-silicon atom to generate met allodisilanetriols C5R5(OC)(2)M-SiCl2-Si(OH)(3) [M = Fe, R = H (5a); M = Ru, R = Me (5b)]. Controlled condensation of 5b with Me2Si(H)Cl lea ds to the novel rutheniosiloxane C5Me5 (OC)(2)Ru-SiCl2-Si(OSiMe2H)(3) (6).